Hi matt
Instead of getting the X and Y pieces mate looking at stock and hrc ones the only difference seams to be the jets inside. So if you match the jets and just make replacement jets to put in stock X and Y pieces that should work it would be easy to test and get them to have correct air flow.
the emulsion tubes would be easy .That leaves the needles if can get the tappers of the hrc ones lenght. single,double or triple taper ?then it would be easy to get them made up.
I think most owners would like a kit, people are paying $300-600 for the hrc ones when avaliable .